Dishwashing machine



Filed Dec. 29, 1958 INVENTOR WILLJAM :1. uzanuzm EL /Jami ATTORNEY Nov.15,1960 w. J. HEERLEIN 2,960,093

DISHWASHING MACHINE Filed Dec. 29, 1958 2 Sheets-Sheet 2 F'lGZ INVENTOR.

WILLIAM :r. HEERLEIN HIS ATT RNEY Unite DISHWASHING MACHINE Filed Dec.29, 1958, Ser. No. 783,369

2 Claims. (Cl. 134-182) This invention relates to dishwashing machines,and more particularly to dishwashers of the type having reversiblerotary water circulating and tub draining means effective to perform onefunction in one direction of rotation and the other function whenrotating in the opposite direction.

The general object of the invention is to provide a dishwasher of thistype in which the circular flow of water on the bottom of the dishwashertub is partially interrupted in such a way that both washing action andtub draining action are improved.

Further objects and advantages of the invention will become apparent asthe following description proceeds, and the features of novelty whichcharacterize the invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

Briefly stated, in accordance with one aspect of this invention there isprovided a dishwasher including a rotary wash impeller and a drain pumpinlet opening centrally located at the bottom of the dishwasher tub, apump impeller connected for rotation with the wash impeller, and agenerally radial vortex interrupting vane mounted on the bottom wall ofthe tub and positioned so that it directs Water into the pump inlet whenthe impellers rotate in the pumping direction and also increases thevelocity and circulation rate of water circulated in the tub when theimpellers rotate in the Washing direction.

For a better understanding of this invention reference may be made tothe following description and the accompanying drawing in which:

Fig. 1 is a front elevation view of a dishwasher incorporating thepresent invention, some of the parts being broken away to show detailsof construction.

Fig. 2 is a fragmentary cross sectional view taken along the line 22 inFig. 1.

Fig. 3 is an enlarged fragmentary cross section view taken along theline 33 in Fig. 2. v

Fig. 4 is an enlarged fragmentary cross sectional view taken along theline 44 in Fig. 3.

Referring to Fig. l of the drawing, there is shown a dishwasher havingan enclosed washing compartment or tub I of generally rectangularconfiguration provided with a generally cone-shaped bottom wall 2. Anupper rack 3 and a lower rack 4 are mounted in tub 1 and arranged tosupport dishes or the like during the washing operations. The dishwasheris provided with a water inlet valve 5 adapted to be connected to awater supply system, a water inlet conduit 6, and a fill funnel 7communicating with the interior of tub 1, these components being mountedon the front wall of the tub and enclosed by a front panel 8. The topaccess opening of tub 1 is closed by hinged top cover 9 during washingoperations, being held in closed position by a latch mechanism 10 whichmay include an interlock arrangement mechanically associated with asequence control device or timer generally designated by the numeral10a. A sheathed heating element 11 mounted on bottom wall 2 is providedto maintates Patent 2,960,093 Patented Nov. 15, 1960 tain wash watertemperature and to heat the air in the tub during the drying period.

A drain pump 12 is supported beneath the tub 1, pump 12 having agenerally circular inlet opening 13 communicating with the tub, anoutlet 14 connected to drain conduit 15, and a housing 16 arranged tosupport a reversible electric motor 17. It will of course be understoodthat conduit 15 is adapted to be connected to a plumbing drain system,and that the conduit extends above the maximum static water level intub 1. Thus water entering the tub is retained therein until dischargedby pump 12. Pump 12 is secured to bottom wall 2 of the tub by anysuitable means such as a pair of semi-circular clamps 18 and 19 whichcooperate with a flanged portion of the pump housing and an annularflange fixedly secured to tub wall 2. Shaft 20 of motor 17 projectsupwardly through pump 12 and supports both a pump impeller 21 and a washimpeller 22 for rotation in both clockwise and counterclockwisedirections.

Wash impeller 22 is provided with blades arranged to circulate waterradially and upwardly throughout the washing compartment formed by tub Iwhen the impeller rotates in the clockwise direction, as viewed in Fig.2. Because of the configuration of the impeller blades, however, nowater is circulated in the washing compartment when the wash impellerrotates in the counterclockwise direction although some rotary movementof water on the bottom wall 2 occurs under these circumstances. Pump 12and in particular pump impeller 21 are arranged so that water in tub 1is rapidly pumped out upon rotation of the two impellers and theircommon shaft 20 in the counterclockwise direction but that substantiallyno pumping action takes place when these parts rotate in the clockwisedirection. One suitable dishwashing and pumping arrangement of this typeis disclosed and claimed in application Serial No. 671,070 filed July10, 1957, by Russell M. Sasnett et al. and assigned to the assignee ofthe present application. As disclosed therein, a complete dishwashingcycle includes a number of washing and rinsing steps followed by adrying period. At the beginning of each washing or rinsing step apredetermined quantity of water is admitted to tub 1 whereupon motor 17is energized so as to rotate shaft 20 and the impellers connectedthereto in a clockwise direction and thus circulate water throughout thewashing compartment. When the charge of water used during this step is:to be discharged from the tub, motor 17 is reversed so as to driveshaft 2% in the counterclockwise direction thus rendering pump impeller21 effective to pump water from the tub to discharge line 15. Ittisevident that the total time required for a complete dishwashing cycledepends to a considerable extent on the length of time required to filland drain the Washing compartment as well as the time actually consumedduring washing and rinsing operations. When it is considered that fiveor six Washing and rinsing steps are often utilized in currentlyproduced dishwashers it will be seen that any appreciable reduction inthe time required to completely drain the washing compartment may make asubstantial contribution to the shortening of the complete washingcycle.

In accordance with the present invention, a vortex interrupting blade orvane 23 is mounted on bottom wall 2 of the washing compartment formed bytub I so as to partially interrupt the rotary or circular flow or waterin the bottom of the tub during washing as well as pumpout operations.Vane 23 includes an upstanding baffle 24 and a horizontal mountingflange portion 25 which may be secured to bottom wall '2 by any suitablemeans such as screws 26. It will of course be understood that suitablesealing means for preventing leakage of water through the screw openingsshould be provided.

Vane 23 extends generally radially from pump inlet opening 13 with itsradiallyoutermost end angularly displaced clockwise from a radial linepassing through its innermost end to an extent such that the vane liessub stantially along a line tangent to the edge of inlet opening-"1 3.-it has been'found that pump-out time may be minimized by positioningvane 23 inthis manner and that substantial departure from this angleof'in'clination (in either direction) results in an increase in pump-outtime. Also, itis desirable that a portion of vane 23 be located directlybelow the path 'of rotation of wash impeller 22, since this arrangementprovides improved washing action, as will be described below.

During'washing operations, when impeller 22 rotates in a clockwisedirection, vane 23 performs two useful functions; First, vane 23 servesas a dam to reduce the velocity of the layer of water flowing in acircular pattern on bottom wall 2 and thus increases the relativevelocity of the blades of impeller 22 with respect to the waterparticles with' which it comes into contact as it rotates. Hence, theenergy imparted to the water particles by the impeller'is increased, andmore vigorous washing'action results. In addition, a wall of water tendsto build up along vane 23, and each time one of the blades of impeller22 passes over the vane the quantity of wa ter thrown upwardly andoutwardly by the blade'momen-tarily increases with the result thatthe-quantity of water thrown up by the bladesfrom this particular pointis greater than that thrown up from any other point around the impellerpath. It has been found that this increased water charge follows anupwardly inclined spiral path and is concentrated in a region in theupper portion of the washing compartment at a point approximately 180degrees from vane 23. Thus it will be seen that a zone of maximumwashing action may be provided in the upper rack area of the washingcompartment and that racks for hard to wash items such as silverware maybe located in this area.

While I have shown and described a particular embodiment of myinvention, I do not desire the inventionto be limited to the particularconstruction disclosed, and I intend by the appended claims to cover allmodifications within the true spirit and scope of my invention.

What I claim is:

1. A dishwasher comprising a tub including side and bottom walls forminga washing compartment, a wash impeller mounted in said tub adjacent thecentral portion of said bottom wall for rotation on a vertical axis,

vsaid wash impeller including a blade member arranged to circulate waterradially and upwardly throughout said washing compartment when said washimpeller is rotated in a first direction, a pump mounted adjacent thebottom wall of said tub, said bottom wall having a centrally locatedgenerally circular opening therein concentric with the axis of said washimpeller and communicating with said pump so as to provide an inletthereto, a pump impeller in said pump connected for rotation with saidwash impeller and arranged to pump water from said tub only whenrotating in a second direction opposite to said first direction, meansfor selectively rotating said impellers in said first and seconddirections, and a vortex interrupting vane mounted on said bottom walladjacent said opening, said vane extending generally radially from saidopening along a line substantially tangent to the edge thereof, theradially outermost end of said vane being angularly displaced in saidfirst direction with respect to a radial line passing through itsinnermost end the vane extending upwardly from the bottom of the tub andterminating closely adjacent the path of rotation of the wash impeller,whereby the vane serves as a dam when the wash impeller is rotated inthe first direction to reduce the velocity of the water and deflect itinto the impeller to provide a charge of water concentrated at apredetermined position in the tub.

2. A dishwasher comprising a tub including side and bottom walls formingawashing compartment, a wash impeller mounted in'said tub adjacent thecentral portion of said bottom wall for rotation on a vertical axis,said wash impeller including a blade member arranged to circulate waterradially and upwardly throughout said washing compartment when saidwash'impeller is rotated in a first direction, a pump mounted adjacentthe bottom wall of said tub, said' bottom wall having a centrallylocated generally'circular-opening therein concentric with the axis ofsaid wash impeller and communicating with said pump so as to provide aninlet thereto, a pump impeller in said pump connected for rota-tion withsaid wash impeller and arranged to pump water from said tub only whenrotating in a second direction opposite to said first direction, meansfor selectively rotating said impellers in said'first and seconddirections, and a vortex interrupting vane mounted on said bottom walladjacent said opening, said vane extending generally radially from saidopening along a line substantially tangent to the edge thereof, theradially outermost end of said vane being angularly displaced in saidfirst direction with respect to a radial line passing through itsinnermost end, a portion of said vane underlying the path of rotation ofsaid impeller,

portion of the vane terminating closely adjacent the underside of thepath of rotation of the wash impeller, whereby the vane serves as a damwhen the Wash impeller is rotated in the first direction to reduce thevelocity of the water and deflect it into the impeller to provide acharge of water concentrated at a predetermined posi-' tion in the tub.

References Cited in the file of this patent UNITED STATES PATENTS

